1. Field of the Invention
This invention relates to the field of polyurethanes. More particularly, this invention relates to the use of particular novolak polyols used in preparing polyurethanes and more particularly, polyurethane foams such as those in rigid form.
2. Description of the Prior Art
Novolak resins of various types have been prepared over a considerable length of time. These include those novolaks prepared from phenol or phenol derivatives and various dioxanes. References to novolaks of this type include Kagan et al, Chem. Abstracts 62, 2889 (1965); Lesage, J. and Peinado, M., Bull. Soc. Chem., France, 1969 (11) 4147-51, "Phenolysis of 4-monosubstituted 1,3-dioxanes"; French Patent No. 1,363,211; British Patent No. 920,413; and J. of Applied Polymer Science, Vol. 8, pp. 1921-1939 (1964). However, to date, novolak resins prepared by utilizing substituted m-dioxanes have not been proposed for use in polyurethanes.
It therefore becomes an object of the invention to provide specific novolak resins as a polyol source useful in preparing polyurethanes.
A specific object of the invention is to provide alkoxylated novolak resins which have low friability, and yet possess other desirable characteristics such as acceptable dimensional strength, humid aging, etc.
Yet another object of the invention is to provide unique polyurethane foams, and particularly rigid polyurethane foams utilizing certain alkoxylated novolaks as the polyol source.
Still further objects in the entire scope of the applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the detailed description.